The shop manual shows the tab that holds the 8 pin in place is on top & pins are 1 to 8 left to right. BTW, have you pulled the codes? a bad speed sensor will give a 27 or 29.

 

Don't know how to pull the codes. Should I interpret a dead short as a bad speed sensor and start from there.

Might be a good idea to change out the sensor before attacking the tranny guy.

 

I have a section in the tech info thread on pulling the codes from the RABS module and the ECU (eec-iv).

 

A dead short is not good. Try pulling the connector off of the speed sensor & hook up your ohm meter directly to it, should see 200-350 ohms. Like Ken sez, try pulling the codes using the method at his link or just buy a scanner for 20 bucks at Walmart.

 

When I did not get a logical reading at the 4X4 control module I disconnected the 10 pin connector at the t-case shift motor and went directly to the two pins connected to the magnetic pickup. This yielded a dead short on my digital multimeter. I pulled the sensor from the case to check for foriegn matter on the magnet but it was clean except for some fluid from the t-case (assuning this is normal). I found a sensor at my local dealer for about $50 so I am going to get it and ohm it our b4 installing it to see if there is a difference. I will let you know what I find out.

 

Had to order the sensor but I pulled the codes off the truck today and it passes everything. Straight 11's. I will install the sensor lext week and see if there is any difference.

 

Ok we are making progress. Before opening the package the new speed sensor came in I checked the resistance wiht the digital meter. It showed a short too. Well it has been a long time since I used a metter for anything but open and short and I had it on a range that didn't work. Once I got my head out of my cavity I was able to read 320 ohms on the new sensor.

With this in mind I wanted to check the old one using the proper range and walla it read 320 ohms, which is good.

I only had one thing left to try and that was the neutral switch, so here is what I did.

I pulled the 4X4 controller out of the dash and rigged up a jumper to Pin 1 of the eight pin connector.

with the contrller thinking it had a completed circuit the t-case slid in and out of low like a champ. Remove the jumper and it flashed. re-connect and it did what it was supposed to.

Since we had tranny work done recently (it is leaking) we took it back and they are going to check out the neutral switch, however if we just can't get the switch to provide the connection I am thinking about mounting a momentary push button to give the controller what it needs to see.

Will still have to come to a stop to please the speed sensor but then a push of the momentary switch will let it shift into low.

Any thoughts on this back yard engineering.

Tim

 

I am guessing, but I imagine the neutral start switch is the same used for the electronic 4x4 shift. If so, see if it will start in neutral, if not, then there is a problem with either the switch or wiring. Sounds like a good work around. But I would still find the real problem at least one of these days

 

The poor tranny man was baffled as to what I was even talking about. His comment was "If it starts in neutral thats all I worry about".

I am sure it is probably either the netral switch on the left side of the tranny towards the front. Takes special socket to remove it. If I am ever doing anything to the tranny again I will pull it and replace it. Thanks for the help gentlemen.